Measurements of mass and angular distributions of fission fragments from actinide nuclei $^{249}$Bk and $^{257}$Md, produced in fusion reactions $^{11}$B and $^{19}$F + $^{238}$U, are presented. Experimentally observed mass ratio distributions indicate “multi-chance fission” through the interplay of fission modes in the fission process, and they agree well with predictions from calculations using the GEF (“GEneral description of Fission observables”) model code. Furthermore, to test the signatures of events from non-compound nuclear processes in the fission of $^{249}$Bk and $^{257}$Md nuclei, Monte Carlo statistical decay model calculations using GEMINI$^{++}$ were performed for the measured mass distribution at all energies. For comparison purposes, the fission fragment mass distributions of neighboring heavy actinide nuclei, previously measured in the fission of $^{250}$Cf and $^{254}$Fm nuclei produced by $^{12}$C and $^{16}$O projectiles on a $^{238}$U target, are also presented. The measured angular anisotropy data for the $^{19}$F + $^{238}$U reaction differ from the results of the Transition State Model (TSM) at energies below the fusion barrier. As a result of the present study, we suggest considering the interplay between K relaxation time, dynamic dissipation, and their influence on shell correction to understand the evolution of fission dynamics in heavy-ion-induced actinide nuclei.

Poland

R. Dubey

France

G. Kaur

India

Abhishek Yadav

N. Saneesh

Akhil Jhingan

P. Sugathan

Italy

Tathagata Banerjee

K.S. Golda

Hardev Singh

Meenu Thakur

United States

Ruchi Mahajan

Re-investigation of the interplay of fission modes and non-equilibrium fission processes in heavy actinide nuclei Bk and Md

This paper presents a comprehensive analysis of the MD-BFKL equation, considering both shadowing and anti-shadowing effects in gluon recombination processes. By deriving analytical expressions for unintegrated gluon distributions through the solution of the MD-BFKL equation, with and without the incorporation of the anti-shadowing effect, we offer new insights into the influence of these effects on the behavior of unintegrated gluon distributions. Our results, when compared to those from the CT18NLO gluon distribution function, demonstrate that the anti-shadowing effect has a notably stronger impact on the characteristics of unintegrated gluon distributions, particularly in regions of high rapidity and momentum. This work significantly contributes to the understanding of gluon recombination mechanisms and their implications in high energy physics.

China

Xiaopeng Wang

Yanbing Cai

Xurong Chen

Exploring the impact of anti-shadowing effect on unintegrated gluon distributions in the MD-BFKL equation  

The Schur index of the Higgs branch of 4-dimensional   <math> <mi>N</mi> </math>  $$ \mathcal{N} $$  = 2 SCFTs is related to the spectrum of non-unitary 2-dimensional CFTs. The rank 1 case has been shown to lead to the non-unitary CFTs with Deligne-Cvitanovic (DC) exceptional sequence of Lie groups. We show that a subsequence (A 0 ,   <math> <msub> <mi>A</mi> <mfrac> <mn>1</mn> <mn>2</mn> </mfrac> </msub> </math>  $$ {A}_{\frac{1}{2}} $$  , A 1 , A 2 , D 4) within the non-unitary sequence is related to a subsequence in the Mathur-Mukhi-Sen (MMS) sequence of unitary theories. We show that 2D non-unitary G 2 theory is related to unitary E 6 theory, and using this result along with the Galois conjugation, we propose that the G 2 Higgs branch is a sub-branch of the E 6 Higgs branch.

Md. Abhishek

Sachin Grover

Dileep Jatkar

United Kingdom

Kajal Singh

Looking for the G 2 Higgs branch of 4D rank 1 SCFTs

We study on-shell functions in the kinematic space for the Coulomb branch of  $$\mathcal{N}$$  = 4 SYM. We construct BCFW bridges that help us build bigger on-shell functions. As a consequence, we provide on-shell diagram formulations for BCFW shifts that correspond to various mass configurations. We will use this to calculate the quadruple cut for the one-loop amplitude on the Coulomb branch and maximal cuts for higher-loops. We make preliminary comments on finding the inequivalent set of on-shell functions for the Coulomb branch.

Subramanya Hegde

Arnab Saha

Amit Suthar

On-shell functions on the Coulomb branch of  $$\mathcal{N}$$  = 4 SYM

We study four point planar loop amplitudes at an arbitrary point in the Coulomb branch of   <math> <mi>N</mi> </math>  $$ \mathcal{N} $$  = 4 super-Yang-Mills theory. We study two particle unitary cuts up to four loop order. We explicitly verify that bubble and triangle graphs do not contribute at one loop level and show that the results hold at higher loop level as well. We also write down an all loop recursion relation for two particle reducible graphs for four point amplitudes.

Loop amplitudes in the Coulomb branch of   <math> <mi>N</mi> </math>  $$ \mathcal{N} $$  = 4 super-Yang-Mills theory

Generalised bi-adjoint scalar amplitudes, obtained from integrations over moduli space of punctured ℂℙ k − 1, are novel extensions of the CHY formalism. These amplitudes have realisations in terms of Grassmannian cluster algebras. Recently connections between one-loop integrands for bi-adjoint cubic scalar theory and   <math> <msub> <mi>D</mi> <mi>n</mi> </msub> </math>  $$ {\mathcal{D}}_n $$  cluster polytope have been established. In this paper using the Gr (3, 6) cluster algebra, we relate the singularities of (3, 6) amplitude to four-point one-loop integrand in the bi-adjoint cubic scalar theory through the   <math> <msub> <mi>D</mi> <mn>4</mn> </msub> </math>  $$ {\mathcal{D}}_4 $$  cluster polytope. We also study factorisation properties of the (3, 6) amplitude at various boundaries in the worldsheet.

One-loop integrand from generalised scattering equations